test: add vitest config and unit tests

src/__tests__/router/guard.spec.ts

@@ -0,0 +1,90 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { createRouter, createMemoryHistory } from 'vue-router'
+
+// We test the guard logic by importing the router and simulating navigation
+// The router in src/router/index.ts uses createWebHistory which requires DOM,
+// so we'll test the guard logic by recreating the key patterns.
+
+describe('route guards', () => {
+  beforeEach(() => {
+    localStorage.clear()
+    vi.restoreAllMocks()
+  })
+
+  function buildRouter() {
+    return createRouter({
+      history: createMemoryHistory(),
+      routes: [
+        { path: '/login', component: { template: '<div/>' }, meta: { requiresAuth: false } },
+        { path: '/welcome', component: { template: '<div/>' }, meta: { requiresAuth: true } },
+        { path: '/study', component: { template: '<div/>' }, meta: { requiresAuth: true } },
+        { path: '/', redirect: '/login' },
+      ],
+    })
+  }
+
+  it('redirects unauthenticated user from protected route to /login', async () => {
+    const router = buildRouter()
+    router.beforeEach((to, _from, next) => {
+      const isLoggedIn = localStorage.getItem('isLoggedIn') === 'true'
+      if (to.meta.requiresAuth && !isLoggedIn) {
+        next({ path: '/login' })
+      } else {
+        next()
+      }
+    })
+
+    await router.push('/welcome')
+    await router.isReady()
+    expect(router.currentRoute.value.path).toBe('/login')
+  })
+
+  it('allows authenticated user to access protected route', async () => {
+    localStorage.setItem('isLoggedIn', 'true')
+    const router = buildRouter()
+    router.beforeEach((to, _from, next) => {
+      const isLoggedIn = localStorage.getItem('isLoggedIn') === 'true'
+      if (to.meta.requiresAuth && !isLoggedIn) {
+        next({ path: '/login' })
+      } else {
+        next()
+      }
+    })
+
+    await router.push('/welcome')
+    await router.isReady()
+    expect(router.currentRoute.value.path).toBe('/welcome')
+  })
+
+  it('allows unauthenticated access to /login', async () => {
+    const router = buildRouter()
+    router.beforeEach((to, _from, next) => {
+      const isLoggedIn = localStorage.getItem('isLoggedIn') === 'true'
+      if (to.meta.requiresAuth && !isLoggedIn) {
+        next({ path: '/login' })
+      } else {
+        next()
+      }
+    })
+
+    await router.push('/login')
+    await router.isReady()
+    expect(router.currentRoute.value.path).toBe('/login')
+  })
+
+  it('root path redirects to /login', async () => {
+    const router = buildRouter()
+    router.beforeEach((to, _from, next) => {
+      const isLoggedIn = localStorage.getItem('isLoggedIn') === 'true'
+      if (to.meta.requiresAuth && !isLoggedIn) {
+        next({ path: '/login' })
+      } else {
+        next()
+      }
+    })
+
+    await router.push('/')
+    await router.isReady()
+    expect(router.currentRoute.value.path).toBe('/login')
+  })
+})